This invention relates to a system for holding food in a ready-to-serve state.
In large commercial kitchens it has become common practice to prepare and freeze food several days before it is served so that a few hours prior to being served it can be thawed, divided into portions, made up and, until served, placed on plates that allow the food to be cooled and/or reheated and kept warm.
An earlier design of a warm-up and cooling tray for ready-to-serve food, described in U.S. Pat. No. 5,941,077, features two heat-conducting plates in an enclosure, two Peltier elements positioned underneath these plates, a control device for switching the Peltier elements into a plate-cooling or plate-heating mode, as well as selector switches for selecting the desired mode and temperature.
That type of heating and cooling tray, however, cannot produce plate temperatures that lead to ready-to-serve temperatures within the food in line with current requirements in terms of hygienic considerations, for instance 65xc2x0 C. (150xc2x0 F.) in Europe.
It is therefore the objective of this invention to provide a system for holding food in ready-to-serve state, permitting compliance with current hygienic requirements.
According to the invention this is accomplished with the functional features specified in claim 1. Desirable design variations are described in the subclaims.
The system for holding food in a ready-to-serve state encompasses the following:
one or several heat-conducting plates that can accommodate the food items directly or in containers, ready to be served;
one or several Peltier elements or similar devices as well as one or several heating elements that are or can be coupled to the plate and/or to the containers;
one or several selector switches as well as radio-signal receivers for selector switches by means of which it is possible to select temperatures and/or temperature cycles and/or plate heating and cooling modes; and
a control system capable of activating the Peltier element(s) in accordance with the selection made via the selector switches for the cooling of the plate(s) and, correspondingly, of activating the Peltier element(s) and/or the heating elements for heating the plate(s).
Due to the fact that heating elements can heat the plate(s) more quickly and/or to higher temperature levels than is possible with Peltier elements alone, temperatures can be obtained within the food items that meet the current hygienic requirements.
Specifically, the heating element(s) is/are positioned under the bottom surface of the plate(s) and is/are preferably in the form of sheet- and/or foil-type and/or thin-film and/or screen-printed heaters.
The plate(s) is/are preferably made from a glass-ceramic material but may alternatively consist of metal, glass, ceramics or stone. It is/they are preferably mounted on a horizontal, circular frame that sits on a base whose bottom is closed.
The plate(s) may be snapped onto the frame and/or the frame onto the base. The dimensions of the frame and/or the base specifically correspond to one or several standards of the restaurant trade.
Viewed from the side, the frame and base are inversely symmetrical. The frame preferably accommodates the selector switches and/or their associated radio-signal receivers and/or the control system while the base houses a power supply and/or a cooling fan. Mounted on the bottom surface of the base are two mutually parallel skids.
The Peltier element(s) is/are primarily located on the bottom surface of the plate(s) and/or on the bottom surface of the heating element(s).
The plate(s) may be heated at the selected temperature and/or temperature cycle by means of the Peltier element(s). In that case the temperatures and/or temperature cycles selected would primarily be warming temperatures or warming cycles.
It is also possible, however, to heat the plate(s) to/at the selected temperature or temperature cycle either by means of the heating elements alone or jointly with both the Peltier element(s) and the heating element(s). In that case the temperatures and/or temperature cycles selected would typically be warming or cooking temperatures or, respectively, warming or cooking cycles, with warming temperatures and warming cycles attainable and controllable more rapidly and with less delay than with the sole use of Peltier elements.